Airborne fraction of C02 has not risen in past 150 years, new research finds
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anuary 2, 7:27 PM Ft. Lauderdale Science News Examiner Anna Sanclement
New studies have found that most of the CO2 emitted by man does not stay in the atmosphere as previously believed. Instead, it is absorbed by terrestrial ecosystems and the oceans.
Some studies have suggested that this absorbing ability has been decreasing and that the airborne fraction has started to increase. Hence, with such contradicting findings, it is imperative that an accurate outlook is achieved to be able to predict climate change more efficiently.
To figure out if the airborne fraction is in fact increasing, Wolfgang Knorr of the department of Earth Sciences at the University of Bristol looked through and analyzed atmospheric carbon dioxide and emission data from the past 150 years. He found that there has been no increase in the airborne fraction of carbon dioxide since 1850, or even during the last five decades.
This could indeed change how scientists are assessing future climate change due to CO2, such as warming, since the phenomenons they are using to correlate them are at risk of being faulty.
These research findings have been published in Geophysical Research Letters.
Is the airborne fraction of anthropogenic CO2 emissions increasing?
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Department of Earth Sciences, University of Bristol, Bristol, UK
Several recent studies have highlighted the possibility that the oceans and terrestrial ecosystems have started loosing part of their ability to sequester a large proportion of the anthropogenic CO2 emissions. This is an important claim, because so far only about 40% of those emissions have stayed in the atmosphere, which has prevented additional climate change. This study re-examines the available atmospheric CO2 and emissions data including their uncertainties. It is shown that with those uncertainties, the trend in the airborne fraction since 1850 has been 0.7 ± 1.4% per decade, i.e. close to and not significantly different from zero. The analysis further shows that the statistical model of a constant airborne fraction agrees best with the available data if emissions from land use change are scaled down to 82% or less of their original estimates. Despite the predictions of coupled climate-carbon cycle models, no trend in the airborne fraction can be found.
Received 18 August 2009; accepted 23 September 2009; published 7 November 2009.
Citation: (2009), Is the airborne fraction of anthropogenic CO2 emissions increasing?, Geophys. Res. Lett., 36, L21710, doi:10.1029/2009GL040613.
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Don Shaw
Walt,
Thanks for your post. It contributes to a better understanding of the subject matter.
Based on a quick reading, one comment in particular is especially troubling to me since the Science seems weak in regards to the residence time of CO2 in the Atmosphere. I suspect the science is not settled on this subject, but I am not the expert.
Your comment:
“Second, the carbon emitted by humans has a distinct chemical signature from natural carbon and we see that it is carbon with that human signature that is increasing and not the natural carbon.”
This is totally inconsistent with a recent paper cited below indicating that the portion of man induced CO2 has remained constant:
“To figure out if the airborne fraction is in fact increasing, Wolfgang Knorr of the department of Earth Sciences at the University of Bristol looked through and analyzed atmospheric carbon dioxide and emission data from the past 150 years. He found that there has been no increase in the airborne fraction of carbon dioxide since 1850, or even during the last five decades.”
See
Your comments on this referenced paper would be appreciated along with reference to scientific studies that support your claim. I have seen computer studies that support your claim however they are nonsense since the programer made assumptions in the model that were not scientifically validated.
Your comments are greatly appreciated.
Again thanks for your posting.
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MAN this is a huge POINT...ISSUE....WHATEVER*********
ANYBODY got a membership for this Publication....?
Probably need a thread starting with this...since nobody is going to get down to this depth of what is becoming a disjointed thread.....